目的：三室动力学模型能够表征疲劳发展的一般状态。本研究拟建立50%等长峰值力矩(The Isometric Peak Torque, IPT)下的髋、膝和踝关节的等张肌耐力三室动力学疲劳模型，为生物力学和运动科学等领域的仿真负荷评价提供理论基础。 方法：分别测量40名男大学生髋、膝和踝关节的IPT后，再以50%IPT进行至力竭的三关节等张肌耐力测试。同步采集下肢主要肌群的肌电和保持时间(Endurance time, ET)。验证以往研究推荐的F和R参数所建立模型所获得的ET和实验ET值的差异，再通过实验ET值和网格搜索的方法匹配合适的F和R参数，以建立正确的三室动力学模型。 结果：（1）髋和踝关节的ET显著大于膝关节 (p < 0.01);（2）以往研究推荐参数建立模型获得的ET显著大于实验测得ET (p < 0.01)，对应的RMSE和MRE数值表现较大；（3）网格搜索法匹配到了三关节等张肌耐力测试的三室模型F和R参数，新建立模型获得ET与实验ET无统计学差异。 结论：所建立模型能够作为同类活动负荷评估的间接测量工具。

Objective: A three-compartment kinetic model can predict the general progression of fatigue. This study aims to develop a three-compartment kinetic fatigue model for the isometric muscle endurance of the hip, knee, and ankle joints at 50% Isometric Peak Torque (IPT), offering a novel approach for simulation-based assessments and load evaluations in biomechanics and sports science. Methods: The IPT of the hip, knee, and ankle joints is measured in 40 male university students. Isometric endurance tests are then performed on all three joints at 50% IPT until exhaustion. Electromyography (EMG) data and endurance time (ET) of major lower limb muscles are collected concurrently. The differences between ETs predicted by models based on previously recommended F and R parameters and actual ETs are analyzed. Subsequently, experimental ETs are used in a grid search to optimize F and R parameters, allowing for the development of an accurate three-compartment kinetic model. Results: (1) The ET of the hip and ankle joints is significantly longer than that of the knee joint (p < 0.01). (2) Models using previously recommended F and R parameters overestimate ET, with significantly higher predicted values than experimentally measured ET (p < 0.01), as well as elevated RMSE and MRE values. (3) The grid search successfully identifies F and R parameters for the three-compartment model, with no statistical difference between model-predicted ET and experimental ET. Conclusion: The developed model can serve as an indirect measurement tool for evaluating load in similar activities.

X914;R135;G804.6